O2 sensor...strange problem

[98gsrDc2]

Hey guys...been having a problem for a while and figured someone might know. I have a 98 gsr and my primary o2 sensor when plugged in causes my car to bog and hesitate at low to moderate acceleraion. At full throttle there is no hesitation. Plugged it in and the cel can b cleared but will immediately start to hesitate. It is a new denso o2 4 wire universal unit and I checked the wiring like 4 times to make sure it was correct. I got the wiring diagram off of here. Unplugged I have no problems whatsoever so this is really bugging me. Also if I leave it plugged in and just kind of deal with the bogging after a while it with throw a too lean code...any info would b a help...thanks :thumbs up

 

[dc2GS-R]

It sounds like you are still having a primary o2 sensor problem. At low throttle angles, the ECU runs in closed loop mode wear it uses feedback from the primary o2 to adjust fuel enrichment on the fly. If, for whatever reason, the ECU is not getting the proper feedback, it will effect the air/fuel ratios during normal driving. When you step on the throttle, the ECU goes into open loop mode, where the o2 sensor is not used and all tuning parameters are drawn from predetermined values in a table. That would explain why it is off during typical driving, but runs fine when getting on it.

 

[98gsrDc2]

:what:

It sounds like you are still having a primary o2 sensor problem. At low throttle angles, the ECU runs in closed loop mode wear it uses feedback from the primary o2 to adjust fuel enrichment on the fly. If, for whatever reason, the ECU is not getting the proper feedback, it will effect the air/fuel ratios during normal driving. When you step on the throttle, the ECU goes into open loop mode, where the o2 sensor is not used and all tuning parameters are drawn from predetermined values in a table. That would explain why it is off during typical driving, but runs fine when getting on it.

thanks for the response...ive put this up once before but i guess it was stumping other people too and i got no response...i am aware of closed and open loop and the problem has got to b something involving my primary but it still leads me to the problem itself. Could a new o2 sensor be no good? Is it possible my 4-1 headers could be causing my o2 sensor to be reading to much flow at low rpm therefore leaning me out so much that its throwing me into limp mode and then throwing a code?..........im so perplexed by this

 

[dc2GS-R]

It is entirely possible that the o2 sensor could be bad. What wiring diagram did you use to wire it in?

The header itself wouldn't cause an o2 issue. The o2 sensor does not read flow, it only detects oxygen content. When low oxygen levels are detected, the ECU will recognize the o2 voltage output as rich and reduce injector duration. The opposite is also true when high oxygen levels are detected, it will recognize that as lean and increase injector duration. It only does this in closed loop mode though. But the sensor itself does not care about flow.